1. Field of the Invention
The present invention relates to an individual guidance system for aircraft under ADS (Automatic Dependent Surveillance) whereby data on the position of the aircraft according to GNSS (Global Navigation Satellite System) are transmitted via AMSS (Aeronautic Mobile Satellite Service) to an air-traffic control system (air-traffic controller's control desk and aircraft data detection device).
2. Description of the Related Art
Hitherto it has been usual for an air-traffic controller to allocate a suitable interval of distance between aircraft (the minimum interval of distance which will allow the aircraft to fly in safety) in order for aircraft to fly in safety without the danger of collision and in order to utilize the air space (a finite area within the sky which is allocated to each air-traffic control body) effectively, and for this purpose ARTS (Automated Radar Terminal System) and similar systems have been employed.
For instance, as FIG. 18 shows, an aircraft 182 within the approach control area (air space within which approach control and terminal control are controlling aircraft in flight), which aims to land on a runway 181 of an airport, flies along a STAR (Standard Terminal Arrival Route: a route which is determined by individual airports and along which arriving aircraft usually fly) to arrive at a final approach fix (point in space in the vicinity of a runway which arriving aircraft must pass through).
In the same way, an aircraft 183 taking off from the runway 181 flies along a SID (Standard Instrument Departure: a route determined by individual airports along which departing aircraft usually fly) to reach its flightpath.
While the individual aircraft are flying along their paths, the approach control area air-traffic controller 184 (a) monitors the radar screen 185 (screen where flight names, positions, altitudes, speeds, courses and other information are displayed), predicts collisions between aircraft on the basis of altitude, speed, course and other factors, and gives instructions by voice communication to the pilot of the aircraft in question in order to avoid such a situation; and
(b) the air-traffic controller 184 monitors the approach control area on the radar screen 185, and gives instructions by voice communication to the pilot of the aircraft in question, prior to its entering the next air space it is due to fly through (in the case of departing aircraft, the air spaces known as sectors which are controlled by air-traffic control; in the case of arriving aircraft, the airport control air space) with regard to changes in altitude, speed and course in order to maintain a distance between aircraft such as is safe and permits the most effective use of the air space.
However, with the conventional method of approach control area control as described above, near misses between aircraft (abnormally close encounters at distances less than those which considerations of safety demand that the aircraft take) and other incidents continue to occur. In other words, there are cases where there is still the likelihood of human error in the judgment of air-traffic controllers, and investigations have shown that this judgment places a considerable weight of responsibility on air-traffic controllers.
Moreover, the amount of air traffic is constantly on the increase, and the potential for human error is expected to rise in proportion to this, or even to outstrip it. It is therefore becoming more and more difficult to predict collisions between aircraft and keep them at a suitable distance, and there are fears that it may prove impossible to maintain standards of safety.
In addition, there is the concept of free flight which is currently the subject of heated debate in the USA. Whereas at present aircraft are allowed to fly only on standard routes, the concept of free flight involves allowing them to fly freely though the air space provided that no collision between aircraft is anticipated. According to this concept, arriving aircraft enter the approach control area from all directions, and it is anticipated that departing aircraft will also do so with a fair degree of freedom after take-off. Consequently, since aircraft will fly through the approach control area also with a certain degree of freedom, the number of flightpaths will increase markedly, and it will become exceedingly difficult to predict collisions between aircraft by human judgment, and to maintain a suitable distance between them until they enter the next air space. For this reason there is urgent need for countermeasures.
It is an object of the present invention, which the authors have designed in view of the situation outlined above, to provide an individual guidance system for aircraft in an approach control area under automatic dependent surveillance which, by supplying the required flight data automatically in units of micro air spaces, permits safe and accurate flight with little scope for human error.